Three-fluid dam-break experiments were conducted to observe the mixing and
stratification processes of three immiscible fluids (two-liquids and one gas) by
gravity. Two liquids (silicone oil and salt water) were separated with a vertical
wall and filled in a rectangle container. Fluid motions are visualized by four sets
of video cameras which are synchronized with each other. Parametric study
reviles the effects of two key fluid properties: kinematic viscosity (or molecular
weight) for silicone oil and density (or concentration) for sodium chloride
aqueous water. After the withdrawal of a vertical partition plate, two liquids
intersected earlier at the center, while the fluids stuck on the walls. The
kinematic viscosity and density difference affect the three-dimensional mixing
and stratification processes significantly. These visual databases are suitable for
a code validation on the interfacial phenomena. Computational multi-phase fluid
dynamics analysis was conducted with Star CCM+ version 8.04. The numerical
results agree with experimental results accordingly for all those key parameters.
The physics behind the contact angle and interfacial tensions are thoroughly
investigated parametrically.
Keywords: gravity-driven stratification, injection, mixture, phase separation,
liquid-liquid, flow visualization, VOF, validation.